Machines are increasingly being fitted with sensors to record and control the functions of the machine and subsystems of the machine. For example, a diesel engine for construction machinery such as, for example, a bulldozer, digger and so forth may include sensors which measure, amongst other variables, injected fuel pressure, mass-flow of air into the engine, engine temperature, oxygen concentration in the outlet gases and so forth, to allow precise adjustments of the fuel/air mix. Similarly, a ship typically includes hundreds, thousands or tens of thousands of sensors measuring parameters such as speed, fuel temperature, stresses in the propeller shafts and so forth. Many ships are powered by marine diesel engines, liquefied natural gas (LNG) engines or combi-fuel engines which may be powered using diesel or LNG. Some ships may include gas-turbine engines. Regardless of the particular type of engine, ship engines similarly include large numbers of sensors for operational, monitoring and diagnostic purposes.
Often, sensors fitted to machines are linked to local electronic processors which control a local process and/or provide a warning or fault message when a physical parameter measured by a sensor moves outside of a predefined range. Such controls and monitoring are based on a local view or on assumptions about the behaviour of a subsystem and interrelated sub-systems of a machine.